Table of contents

0. Math Review31m
- Math Review
  31m
1. Intro to Physics Units1h 29m
2. 1D Motion / Kinematics3h 56m
3. Vectors2h 43m
4. 2D Kinematics1h 42m
5. Projectile Motion3h 6m
6. Intro to Forces (Dynamics)3h 22m
7. Friction, Inclines, Systems2h 44m
8. Centripetal Forces & Gravitation7h 26m
9. Work & Energy1h 59m
10. Conservation of Energy2h 54m
11. Momentum & Impulse3h 40m
12. Rotational Kinematics2h 59m
13. Rotational Inertia & Energy7h 4m
14. Torque & Rotational Dynamics2h 5m
15. Rotational Equilibrium3h 39m
16. Angular Momentum3h 6m
17. Periodic Motion2h 9m
18. Waves & Sound3h 40m
19. Fluid Mechanics4h 27m
20. Heat and Temperature3h 7m
21. Kinetic Theory of Ideal Gases1h 50m
22. The First Law of Thermodynamics1h 26m
23. The Second Law of Thermodynamics3h 11m
24. Electric Force & Field; Gauss' Law3h 42m
25. Electric Potential1h 51m
26. Capacitors & Dielectrics2h 2m
27. Resistors & DC Circuits3h 8m
28. Magnetic Fields and Forces2h 23m
29. Sources of Magnetic Field2h 30m
30. Induction and Inductance3h 38m
31. Alternating Current2h 37m
32. Electromagnetic Waves2h 14m
33. Geometric Optics2h 57m
34. Wave Optics1h 15m
35. Special Relativity2h 10m

28. Magnetic Fields and Forces

Force and Torque on Current Loops

Physics

28. Magnetic Fields and Forces

Force and Torque on Current Loops

Previous problemNext problem

Struggling with Physics?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

A single circular loop of wire has a radius of $2 . 0 cm$ , and carries a current of $4.0 A$ . What is the maximum torque that could be experienced by this loop due to earth's magnetic field?

2.5 \times 10^{- 8} N \cdot m

6.3 \times 10^{- 8} N \cdot m

8.0 \times 10^{- 8} N \cdot m

1.8 \times 10^{- 7} N \cdot m

7.9 \times 10^{- 7} N \cdot m

2.5 \times 10^{- 7} N \cdot m

Previous problemNext problem

Verified step by step guidance

First, understand that the torque (τ) experienced by a current-carrying loop in a magnetic field is given by the formula: τ = n * I * A * B * sin(θ), where n is the number of turns (which is 1 for a single loop), I is the current, A is the area of the loop, B is the magnetic field strength, and θ is the angle between the normal to the loop and the magnetic field.

Calculate the area (A) of the circular loop using the formula for the area of a circle: A = π * r^2, where r is the radius of the loop. Given that the radius is 2.0 cm, convert this to meters (0.02 m) before substituting into the formula.

The maximum torque occurs when sin(θ) = 1, which is when the angle θ is 90 degrees. This simplifies the torque formula to τ = I * A * B.

Substitute the given values into the simplified torque formula: I = 4.0 A, A = π * (0.02 m)^2, and B = Earth's magnetic field strength. Note that Earth's magnetic field strength is typically around 25 to 65 microteslas (T), but you may need to use a specific value if provided.

Calculate the torque using the substituted values to find the maximum torque experienced by the loop. Compare your result with the given options to identify the correct answer.